Hydraulic compression tool

Abstract

A hand-operated hydraulic compression tool for compressing a metal connector about a plurality of wires to be connected. The tool is adapted to make both parallel and butt-type connections of the wires. The tool includes a pressure relief valve for limiting the maximum pressure to be applied to the connector. The valve is removably installed in a cavity of the tool body for facilitated servicing. The tool further includes control structure for releasing the pressure upon completion of a forming operation, the flow passage for the returning hydraulic fluid utilizing a portion of the body cavity receiving the pressure regulating valve.

I claim: 
     
       1. In a hydraulic compression tool for compressing a connector onto a wire end, said tool including a pair of complementary compression dies, means defining a reservoir for holding a supply of hydraulic fluid, a hydraulic force applying means for forcibly urging the dies toward a compressing disposition, a hydraulic pump for delivering hydraulic fluid from said supply under pressure to said force applying means to effect a compressing operation, and means for returning hydraulic fluid from said force applying means to said reservoir to release said dies subsequent to a compression operation, the improvement comprising: means defining a relief flow passage from said force applying means;   body means defining an outwardly opening cavity communicating with said relief flow passage and having an outlet opening to said reservoir; and   valve means readily removably installed in said cavity for controlledly closing said relief flow passage while permitting flow of said hydraulic fluid from said force applying means to said supply means when the pressure of the hydraulic fluid in said force applying means exceeds a preselected maximum operating pressure, said valve means defining a transverse passage opening to said outlet and said means for returning hydraulic fluid to said reservoir includes means for directing the returning fluid through said transverse passage and said outlet to said reservoir.   
     
     
       2. The hydraulic compression tool of claim 1 wherein said valve means is threaded to said body means in said cavity. 
     
     
       3. The hydraulic compression tool of claim 1 wherein said valve means includes a housing secured to said body means in said cavity and having an inlet port opening to said relief flow passage, said inlet port defining a valve seat. 
     
     
       4. The hydraulic compression tool of claim 1 wherein said valve means includes a housing secured to said body means in said cavity and having an inlet port opening to said relief flow passage, said inlet port defining a valve seat, said transverse passage comprising an annular channel opening radially outwardly about said housing in communication with said reservoir through said outlet. 
     
     
       5. The hydraulic compression tool of claim 1 wherein said valve means is recessed within said cavity. 
     
     
       6. In a hydraulic compression tool for compressing a connector onto a wire end, said tool including a pair of complementary compression dies, means defining a reservoir for holding a supply of hydraulic fluid, a hydraulic force applying means for forcibly urging the dies toward a compressing disposition, a hydraulic pump for delivering hydraulic fluid from said supply under pressure to said force applying means to effect a compressing operation, and means for returning hydraulic fluid from said force applying means to said reservoir to release said dies subsequent to a compression operation, the improvement comprising: means defining a relief flow passage from said force applying means to said reservoir;   body means defining an outwardly opening cavity communicating with said relief flow passage; and   valve means readily removably installed in said cavity for controlledly closing said relief flow passage while permitting flow of said hydraulic fluid from said force applying means to said supply means when the pressure of the hydraulic fluid in said force applying means exceeds a preselected maximum operating pressure, said valve means being threaded to said body means in said cavity, and locking means being provided for releasably locking the valve means against threaded withdrawal from the cavity.   
     
     
       7. In a hydraulic compression tool for compressing a connector onto a wire end, said tool including a pair of complementary compression dies, means defining a reservoir for holding a supply of hydraulic fluid, a hydraulic force applying means for forcibly urging the dies toward a compressing disposition, a hydraulic pump for delivering hydraulic fluid from said supply under pressure to said force applying means to effect a compressing operation, and means for returning hydraulic fluid from said force applying means to said reservoir to release said dies subsequent to a compression operation, the improvement comprising: means defining a relief flow passage from said force  applying means to said reservoir;   body means defining an outwardly opening cavity communicating with said relief flow passage; and   valve means readily removably installed in said cavity for controlledly closing said relief flow passage while permitting flow of said hydraulic fluid from said force applying means to said supply means when the pressure of the hydraulic fluid in said force applying means exceeds a preselected maximum operating pressure, said means for returning hydraulic fluid including means defining a return flow passage portion extending through said cavity.   
     
     
       8. The hydraulic compression tool of claim 7 wherein said valve means defines a flow conducting passage within said cavity comprising said return flow passage portion means. 
     
     
       9. The hydraulic compression tool of claim 7 wherein said valve means defines a housing and an outlet means including an annular channel opening radially outwardly about said housing in communication with said supply means, said channel defining said flow conducting passage. 
     
     
       10. The hydraulic compression tool of claim 7 wherein said means for returning hydraulic fluid defines a bypass passage having an inlet communicating with said relief flow passage at a position between said force applying means and said valve means. 
     
     
       11. The hydraulic compression tool of claim 7 wherein said means for returning hydraulic defines a bypass passage having an inlet communcating with said relief flow passage at a position between said force applying means and said valve means and an outlet communicating with an outlet means of said valve means in said cavity.